This is a great question. At least for my own work, I find that we're now at a point where "more"—that is, more sharpness, more megapixels, less noise—really won't add anything to what I'm doing. I mostly shoot tripod-mounted stitched landscape images with file sizes of 0.6 to 1.2 gig, taken at low ISO. Sure, it'd be nice to have a digital pano camera with a huge sensor, but the cost of the existing Seitz version is so laugh-out-loud absurd I'm happy to keep stitching. (I mean, what would you do if you dropped your circa $40,000 Seitz on the pavement? Shoot yourself?) As it is, this gives me the flexibility to pick a focal length appropriate to the image I'm trying to get. I can already print with blade-of-grass sharpness and resolution up to 24x96" or so; any bigger is simply too big to transport & display in a normal home or office.

I can see further room for improvement in terms of high ISO/low noise for candid people photography in low light, but I'd be the first to admit I really suck at that kind of stuff, so it doesn't have much to offer me.

At least for me, I'm better off getting out there to shoot more photographs than obsessing about another tiny incremental improvement in the gear we're using.